Endurance limit of pulsed laser hardened component-like specimens-Experiment and simulation

The pulsed laser hardening with low-pulse frequencies enables a higher hardening depth compared with continuous wave laser hardening. To avoid melting a special pulse-to-pulse temperature control was developed. The temperature during hardening was calculated. Residual stresses after hardening were measured and simulated. Studies of the fatigue strength showed that pulsed laser hardening enables an increase of the fatigue strength of component-like specimens. The endurance limit was simulated with the weakest-link model on the base of hardness, roughness, and residual stresses. The weakest-link model also predicts crack initiation sites which were compared with the observed ones. The described calculations of the residual stresses and the endurance limit are applicable on variable geometries of components. So, in the field of development and construction it is possible to reduce the development cycles.